View source for 2wk9


==Structure of Plp_Thr aldimine form of Vibrio cholerae CqsA==
<StructureSection load='2wk9' size='340' side='right'caption='[[2wk9]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2wk9]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Vibrio_cholerae_O1_biovar_El_Tor_str._N16961 Vibrio cholerae O1 biovar El Tor str. N16961]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2WK9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2WK9 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.9&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=PLG:N-GLYCINE-[3-HYDROXY-2-METHYL-5-PHOSPHONOOXYMETHYL-PYRIDIN-4-YL-METHANE]'>PLG</scene>, <scene name='pdbligand=PLP:PYRIDOXAL-5-PHOSPHATE'>PLP</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2wk9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2wk9 OCA], [https://pdbe.org/2wk9 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2wk9 RCSB], [https://www.ebi.ac.uk/pdbsum/2wk9 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2wk9 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CQSA_VIBCH CQSA_VIBCH] Required for the synthesis of the quorum-sensing autoinducer CAI-1 ((S)-3-hydroxytridecan-4-one) which probably functions as an intragenus signal.
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/wk/2wk9_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2wk9 ConSurf].
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== Publication Abstract from PubMed ==
CqsA is an enzyme involved in the biosynthesis of cholerae autoinducer-1 (CAI-1), the major Vibrio cholerae autoinducer engaged in quorum sensing. The amino acid sequence of CqsA suggests that it belongs to the family of alpha-oxoamine synthases that catalyse the condensation of an amino acid to an acyl-CoA substrate. Here we present the apo- and PLP-bound crystal structures of CqsA and confirm that it shares structural homology with the dimeric alpha-oxoamine synthases, including a conserved PLP-binding site. The chemical structure of CAI-1 suggests that decanoyl-CoA may be one substrate of CqsA and that another substrate may be l-threonine or l-2-aminobutyric acid. A crystal structure of CqsA at 1.9-A resolution obtained in the presence of PLP and l-threonine reveals an external aldimine that has lost the l-threonine side chain. Similarly, a 1.9-A-resolution crystal structure of CqsA in the presence of PLP, l-threonine, and decanoyl-CoA shows a trapped external aldimine intermediate, suggesting that the condensation and decarboxylation steps have occurred, again with loss of the l-threonine side chain. It is suggested that this side-chain loss, an observation supported by mass spectrometry, is due to a retro-aldol reaction. Although no structural data have been obtained on CqsA using l-2-aminobutyric acid and decanoyl-CoA as substrates, mass spectrometry confirms the expected product of the enzyme reaction. It is proposed that a region of structure that is disordered in the apo structure is involved in the release of product. While not confirming if CqsA alone is able to synthesize CAI-1, these results suggest possible synthetic routes.

Insights into the biosynthesis of the Vibrio cholerae major autoinducer CAI-1 from the crystal structure of the PLP-dependent enzyme CqsA.,Jahan N, Potter JA, Sheikh MA, Botting CH, Shirran SL, Westwood NJ, Taylor GL J Mol Biol. 2009 Sep 25;392(3):763-73. Epub 2009 Jul 22. PMID:19631226<ref>PMID:19631226</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 2wk9" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Vibrio cholerae O1 biovar El Tor str. N16961]]
[[Category: Botting CH]]
[[Category: Jahan N]]
[[Category: Potter JA]]
[[Category: Sheikh MA]]
[[Category: Shirran SL]]
[[Category: Taylor GL]]
[[Category: Westwood NJ]]